Thanks for quick answers guys! Puts my mind at rest, but strange then that Avast doesn't take account of its own deletions.... - - either it's too intelligent or it's too thick!!
The files were there when the scan was initiated, housekeeping doesn't stop for scans.
A nightly scan is overkill on a resident on-access antivirus solution. The more on-demand scans that you do the more likelihood that you are going to bump into this reporting of avast VPS files not there.
- With a resident on-access antivirus like avast, the need for frequent on-demand scans is much depreciated. For the most part the on-demand scan is going to be scanning files that would be otherwise be dormant or inert. If they were active files then the on-access file system shield would be scanning them before being created, modified, opened or executed.
I have avast set to do a scheduled weekly Quick scan, set at a time and day that I know the computer will be on. If for some reason my system wasn't on, no big deal I will catch up on the next scheduled scan.